Abstract
Freight by air does not comprise a significant share of the worldwide tonnage due to its cost compared to land (road and rail) and sea transport. However, air freight is important for commodities that either have high values or are time-sensitive. For instance, documents, perishable products, electronics, pharmaceuticals, or emergency shipments of spare parts are commonly shipped by air. Although the demand for air freight could have a more important role in landlocked countries or developing regions where land transport infrastructure is scarce, it is limited because of the imbalances between inbound and outbound flows. Consequently, considering freight traffic volume worldwide concentration and distribution among countries or regions is remarkable when compared with its relative contribution to the global freight volume.
